package com.hyd.security.filter;

import com.hyd.security.security.TokenManager;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.authentication.www.BasicAuthenticationFilter;
import org.springframework.util.StringUtils;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

/**
 * 授权过滤器
 */
public class TokenAuthFilter extends BasicAuthenticationFilter {

    private TokenManager tokenManager;
    private RedisTemplate redisTemplate;
    public TokenAuthFilter(AuthenticationManager authenticationManager,TokenManager tokenManager,RedisTemplate redisTemplate) {
        super(authenticationManager);
        this.tokenManager = tokenManager;
        this.redisTemplate = redisTemplate;
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        //获取当前认证成功的用户权限信息
        UsernamePasswordAuthenticationToken authRequest = getAuthentication(request);
        //判断如果有权限信息，则放到权限上下文
        if(authRequest!=null){
            SecurityContextHolder.getContext().setAuthentication(authRequest);
        }

        //放行
        chain.doFilter(request,response);
    }

    private UsernamePasswordAuthenticationToken getAuthentication(HttpServletRequest request) {
        //从header中获取token
        String token = request.getHeader("token");
        if (token == null) {
            return null;
        }
        String username = tokenManager.getUserInfoFromToken(token);

        //从redis获取对应权限列表
        List<String> permissionValueList = (List<String>) redisTemplate.opsForValue().get(username);

        Collection<GrantedAuthority> authorities = new ArrayList<>();
        for (String permissionValue : permissionValueList) {
            if (StringUtils.isEmpty(permissionValue)) {
                continue;
            }
            SimpleGrantedAuthority authority = new SimpleGrantedAuthority(permissionValue);
            authorities.add(authority);
        }

        return new UsernamePasswordAuthenticationToken(username, token, authorities);
    }
}
